import javax.swing.JOptionPane;
    import java.text.*;
    public class MunKit{
            public static void main(String[] args){
                    DecimalFormat df = new DecimalFormat("#.00");
                    int decision = JOptionPane.YES_OPTION;
                    double paymentDay, paymentNight, amountRegular;
                    do{
                            String accountNo = JOptionPane.showInputDialog(
                                    null,"Please Enter Your Account Number.","Bill Calculator",
                                    JOptionPane.QUESTION_MESSAGE);
                            if(accountNo == null)break;
                            String serviceCode = JOptionPane.showInputDialog(
                                    null,"Please Enter Your Service Code:" + "\nPremium = P / p" +
                                    "\nRegular = R / r","Bill Calculator",JOptionPane.QUESTION_MESSAGE);
                            char charServiceCode = serviceCode.toUpperCase().charAt(0);
                            if(charServiceCode == 'P'){
                                    String serviceType = "Premium";
                                    String calltimeDay = JOptionPane.showInputDialog(
                                            null,"Please Enter Minutes Called During The Day This Month?",
                                            "Bill Calculator (PREMIUM)",JOptionPane.QUESTION_MESSAGE);
                                    double dblCalltimeDay = Double.parseDouble(calltimeDay);
                                    if(dblCalltimeDay < 75 ){
                                            paymentDay = 0;
                                    }else{
                                            paymentDay = (dblCalltimeDay - 75)*0.1;
                                    }
                                    String calltimeNight = JOptionPane.showInputDialog(
                                            null,"Please Enter Minutes Called During The Night This Month?",
                                            "Bill Calculator (PREMIUM)",JOptionPane.QUESTION_MESSAGE);
                                    double dblCalltimeNight = Double.parseDouble(calltimeNight);
                                    if(dblCalltimeNight < 100 ){
                                            paymentNight = 0;
                                    }else{
                                            paymentNight = (dblCalltimeNight - 100)*0.05;
                                    }
                                    double amountPremium = 25 + paymentNight + paymentDay;
                                    JOptionPane.showMessageDialog(null,"Here Is Your Bill Information:" +
                                            "\nAccount No: " + accountNo + "\nService Type: " + serviceType +
                                            "\nCall Time (Day): " + calltimeDay + " minutes" +
                                            "\nCall Time (Night): " + calltimeNight +" minutes" +
                                            "\nAmount Due: RM" + df.format(amountPremium),
                                            "Bill Calculator (PREMIUM)",JOptionPane.INFORMATION_MESSAGE);
                            }else if(charServiceCode == 'R'){
                                    String serviceType = "Regular";
                                    String calltime = JOptionPane.showInputDialog(
                                            null,"Please Enter Minutes Called This Month",
                                            "Bill Calculator (REGULAR)",JOptionPane.QUESTION_MESSAGE);
                                    double dblCalltime = Double.parseDouble(calltime);
                                    if(dblCalltime > 50){
                                            amountRegular = 10 + ((dblCalltime - 50)*0.2);
                                    }else{
                                            amountRegular = 10;
                                    }
                                    JOptionPane.showMessageDialog(null,"Here Is Your Bill Information:" +
                                            "\nAccount No: " + accountNo + "\nService Type: " + serviceType +
                                            "\nCall Time : " + calltime + " minutes" +
                                            "\nAmount Due: RM" + df.format(amountRegular),
                                            "Bill Calculator (REGULAR)",JOptionPane.INFORMATION_MESSAGE);
                            }else{
                                    JOptionPane.showMessageDialog(null,"The Service Code Entered Is Invalid.",
                                    "Bill Calculator (ERROR)",JOptionPane.ERROR_MESSAGE);
                            }
                            decision = JOptionPane.showConfirmDialog(
                                    null,"Would You Like To Restart The Program?","Bill Calculator",
                                    JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE);
                    }while(decision == JOptionPane.YES_OPTION);
            }
    }